Kawasaki introduced the ZX-6R in 1995 with very similar looks and features like the 1994 introduced ZX-9R, including the ram-air intake that had been developed by Kawasaki since the 1990 ZX-11 (ZZ-R1100). The first ZX-6R had a dry weight of 401.2 pounds (182.0 kg), wet weight of 454 pounds (206 kg), and was capable of accelerating 0 to 60 miles per hour (0 to 97 km/h) in 3.6 seconds.
With competition from Honda's CBR600F4i, Suzuki's GSX-R600, and Yamaha's YZF-R6 getting more aggressive, Kawasaki decided to make an unusual move for the late 2002 models. They increased the capacity of the traditional 600 cubic centimetres (37 cu in) motor to 636 cubic centimetres (38.8 cu in) with the ZX-6R A1P. This version used the J series bodywork with the only notable differences being the "636" stickers on the fairing. For riders who needed bikes for displacement-restricted racing, Kawasaki also made available a limited production 599 cubic centimetres (36.6 cu in) version called the Ninja ZX-6RR, but the 636 cubic centimetres (38.8 cu in) ZX-6R would be their main mass production middleweight sport bike. 2003 2004 03 04 ZX6R ZX6-R Z-X6R ZX600 ZX-600 Z-X600